Significance of micro-EGFR T790M mutations on EGFR-tyrosine kinase inhibitor efficacy in non-small cell lung cancer.

Small amounts of epidermal growth factor receptor (EGFR) T790M mutation (micro-T790M), which is detected using droplet digital PCR (ddPCR) but not conventional PCR, in formalin-fixed and paraffin-embedded (FFPE) samples have been investigated as a predictive factor for the efficacy of EGFR-tyrosine kinase inhibitors (TKIs). However, the predictive value of micro-T790M remains controversial, possibly owing to the failure to examine artificial T790M in FFPE specimens. Therefore, we examined the predictive value of micro-T790M in first-generation (1G), second-generation (2G), and third-generation (3G) EGFR-TKI efficacy using a new method to exclude FFPE-derived artificial mutations in our retrospective cohort. The primary objective was time to treatment failure (TTF) of 1G, 2G, and 3G EGFR-TKIs according to micro-T790M status. In total, 315 patients with EGFR-positive non-small cell lung cancer treated with 1G, 2G, and 3G EGFR-TKIs were included in this study. The proportion of patients positive for micro-T790M in the 1G, 2G, and 3G EGFR-TKI groups was 48.2%, 47.1%, and 47.6%, respectively. In the micro-T790M-positive group, the TTF was significantly longer in the 2G and 3G EGFR-TKI groups than in the 1G TKI group. No differences in the micro-T790M-negative group were observed. Micro-T790M status detected using ddPCR, eliminating false positives, may be a valuable predictor of EGFR-TKI efficacy.

Docetaxel Plus Ramucirumab With Primary Prophylactic Pegylated Granulocyte-Colony Stimulating Factor Support for Elderly Patients With Advanced NSCLC: A Multicenter Prospective Single Arm Phase 2 Trial: DRAGON Study (WJOG9416L).

Introduction: Docetaxel plus ramucirumab could be a promising treatment for chemo-naive elderly patients with NSCLC, but high incidence of febrile neutropenia (FN) is a critical concern. We thus adopted a routine primary prophylactic pegylated-granulocyte-colony stimulating factor (PEG-G-CSF) to reduce FN and maximize the efficacy of docetaxel plus ramucirumab in elderly patients. Methods: This is a single arm phase 2 trial for chemo-naive elderly patients (aged ≥75 y) with advanced NSCLC. Docetaxel (60 mg/m2, d 1) plus ramucirumab (10 mg/kg, d 1) with PEG-G-CSF (3.6 mg, d 2) was administered every 3 weeks until progression. The primary end point was overall response rate (ORR) (expected ORR: 35%). Results: Between February 2018 and January 2021, 54 patients were enrolled. Median age was 78 (range: 75-86). A total of 21 (38.9%) partial response, 22 (40.7%) stable disease, nine (16.7%) progressive disease, and two (3.7%) not assessable were confirmed, resulting in ORR of 38.9% (90% confidence interval [CI]: 27.7%-51.0%) and disease control rate of 79.6%. Median progression-free survival and overall survival were 5.2 (95% CI: 4.2-6.9) and 12.7 (95% CI: 10.2-18.9) months, respectively. There were one (1.9%) FN, two (3.7%) bleeding grade greater than or equal to 3, and one (1.9%) treatment-related death (pneumonitis). Pneumonitis occurred in five patients (9.3%). Main adverse events grade greater than or equal to 3 were observed: four (7%) thrombocytopenia; three (5.6%) neutropenia; six (11.1%) hyposodium; five (9.3%) infection; five (9.3%) hypertension; four (7.4%) anorexia; and three (5.6%) oral mucositis. Conclusions: Docetaxel plus ramucirumab with PEG-G-CSF revealed efficacy and safety for chemo-naive elderly patients with NSCLC. Primary prophylactic PEG-G-CSF highly prevented FN.

A Large-Scale Prospective Concordance Study of Plasma- and Tissue-Based Next-Generation Targeted Sequencing for Advanced Non-Small Cell Lung Cancer (LC-SCRUM-Liquid).

PURPOSE: We evaluated plasma cell-free DNA (cfDNA) and tissue-based sequencing concordance for comprehensive oncogenic driver detection in non-small cell lung cancer (NSCLC) using a large-scale prospective screening cohort (LC-SCRUM-Liquid). EXPERIMENTAL DESIGN: Blood samples were prospectively collected within 4 weeks of corresponding tumor tissue sampling from patients with advanced NSCLC to investigate plasma cfDNA sequencing concordance for alterations in 8 oncogenes (EGFR, KRAS, BRAF, HER2, MET, ALK, RET, and ROS1) compared with tissue-based next-generation targeted sequencing. RESULTS: Paired blood and tissue samples were obtained in 1,062/1,112 enrolled patients with NSCLC. Oncogenic alteration was detected by plasma cfDNA sequencing and tissue assay in 455 (42.8%) and 537 (50.5%) patients, respectively. The positive percent agreement of plasma cfDNA sequencing compared with tissue DNA and RNA assays were 77% (EGFR, 78%; KRAS, 75%; BRAF, 85%; HER2, 72%) and 47% (ALK, 46%; RET, 57%; ROS1, 18%; MET, 66%), respectively. Oncogenic drivers were positive for plasma cfDNA and negative for tissue due to unsuccessful genomic analysis from poor-quality tissue samples (70%), and were negative for plasma cfDNA and positive for tissue due to low sensitivity of cfDNA analysis (61%). In patients with positive oncogenic drivers by plasma cfDNA sequencing but negative by tissue assay, the response rate of genotype-matched therapy was 85% and median progression-free survival was 12.7 months. CONCLUSIONS: Plasma cfDNA sequencing in patients with advanced NSCLC showed relatively high sensitivity for detecting gene mutations but low sensitivity for gene fusions and MET exon 14 skipping. This may be an alternative only when tissue assay is unavailable due to insufficient DNA and RNA. See related commentary by Jacobsen Skanderup et al., p. 1381.